I think
http://www.vcdhelp.com might have a guide on doing this. A web search might also help. Yes, it can be done, BUT you need to be aware of something. None of the ways to do it are in allowed according to the specifications for VCD. What people have to do to make it work is pretty nasty and usually involves deliberately corrupting certain things on the disc. If you do make such a VCD, please be aware that people who receive this disc may not be able to play it. Some standalone DVD or VCD players may refuse to play it and of course, PCs are not going to be able to play it at all. Are you prepared to deal with VERY PISSED OFF customers who want a refund because the "piece of crap" VCD you sold them won't play?
Just my opinion, but most of the time people ask about this is because they want to protect stupid stuff like home movies that they transferred to VCD. Maybe if you are making a music VCD or have some sort of video that people may actually want, I can understand wanting to do it, but if you are just trying to protect something that no one has any interest in paying for, you are wasting your time trying to do this. I have no idea what you want to protect, so I admit that you may have a legitimate concern for copy protection. VCD was never designed for any kind of copy protection. If what you want to protect is really worth protecting, why not make a DVD? Most of the general public has no idea how to copy DVDs anyway and they do support copy protection (Macrovision, encryption). Finally, even if you do copy protect your VCD, please note that none of the current copy protection technologies is perfect and a person with good PC technical skills may still be able to bust your copy protection and copy your VCD.
